Unable to save the autoplot image in the for loop

My question is, suppose I have several thousands of mat file data and I want to read them first and then plot them and save the output as a photo image. I encountered a problem in the automatic saving section in the second loop, what should I do??

clc

clear

close all

for i=1:1

number=i+3;

f=num2str(number);

print1=strcat(f);

print=strcat('C:\Users\MASHHADSERVICE\OneDrive\Desktop\armina\data\',f,'.mat');

load(print)

c=cell2mat(Y);

eval(['class', print1 , ' =c;']);

end

for i=1:1

figure(i)

g=eval(['class', print1]);

plot(g)

print3=strcat('a',num2str(i+5),'.png');

saveas(figure(i),print3,'png')

end

[DGM]

Well:

• the code is uncommented and loads any number of unknown things into memory
• you're abusing eval() to unnecessarily create dynamic variables
• you're shadowing common function names which you may or may not be using elsewhere
• the loops only iterate exactly once, and are therefore either superfluous or erroneous
• you haven't mentioned at all what the actual problem is

maybe you should let us know what's actually in the files and what the actual errors are.

Answer 1

[DGM]

clc
clear 
close all

pathprefix = 'C:\Users\MASHHADSERVICE\OneDrive\Desktop\armina\data\';
numfiles = 1;

C = cell(numfiles,1);
for i = 1:numfiles
    % this assumes the numbers have no leading zeros
    infname = sprintf('%d.mat',i+3);
    
    % i'm assuming each file contains only a cell array called Y
    % and that the cell array is convertible to a numeric array
    S = load(infname)
    C{k} = cell2mat(S.Y);
end

for i = 1:numfiles
    % create an unmanageable pile of windows
    figure(i)
    plot(C{k})
    
    % consider using zero padding on filenames
    outfname = sprintf('a%05d.png',i+5);
    saveas(figure(i),outfname)
end

If the only thing that needs to be done is plotting, then the two loops can be combined and the entire cell array is unnecessary. In fact, you probably should do that, since it would be ridiculous to open "several thousand" figure windows at once. There would be no good reason to do such a thing.

clc
clear 
close all

pathprefix = 'C:\Users\MASHHADSERVICE\OneDrive\Desktop\armina\data\';
numfiles = 1;

C = cell(numfiles,1);
for i = 1:numfiles
    % this assumes the numbers have no leading zeros
    infname = sprintf('%d.mat',i+3);
    
    % i'm assuming each file contains only a cell array called Y
    % and that the cell array is convertible to a numeric array
    S = load(infname)

    % create one figure window and reuse it
    figure(1); clf
    plot(cell2mat(S.Y))
    
    % consider using zero padding on filenames
    outfname = sprintf('a%05d.png',i+5);
    saveas(figure(1),outfname)
end

See also:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

[amir]

You didn't understand what I meant, or I told you wrongly, but anyway, I solved my problem by myself using my own code.

This code was just the basics and I asked my own questions for a big project

Unable to post original code here

thank you